The present invention relates to a photographing lens of a camera, particularly to a photographing lens having a light blocking mask located in front of a non-circular lens which receives an optical image from an object and forms an image on a photographing medium.
Conventionally, a compact camera is known, in which a part of a photographing lens is cut and other components are mounted in the cut portion.
For example, Jpn. UM Appln. KOKAI publication No. 5-11116 discloses a compact lens barrel in which upper and lower portions of a photographing lens are cut and an auxiliary optical unit is incorporated in the cut portion.
Further, Jpn. Pat. Appln. KOKAI Publication No. 9-197237 discloses that upper and lower portions of a photographing lens are cut and a supporting member is provided in the cut portion, so that a compact photographing lens can be obtained.
However, as regards the lenses of the cameras described above, since the distance between the optical axis of the photographing lens and the vertex of the lens is reduced by cutting a part of the lens, noise light is generated in relation to the cut portion. The noise light is transmitted to a film and adversely influences the formation of an image on the film.
It is accordingly an object of the present invention to provide a photographing lens of a camera which can block off noise light generated in relation to a cut portion of the lens, so that the formation of an image cannot be adversely influenced.
To achieve the above object, according to a first aspect of the present invention, there is provided a photographing lens of a camera, comprising:
a non-circular lens for receiving an optical image from an object and forming an image on a photographing medium; and
a light blocking mask, fixed in front of the non-circular lens, for blocking noise light generated in relation to the non-circular lens.
According to a second aspect of the present invention, there is provided a photographing lens of a camera, comprising:
a cut lens obtained by cutting off a portion of a circular lens at a position of a predetermined height from an optical axis of the circular lens; and
a light blocking mask arranged immediately in front of the cut lens and having an opening which allows passage of an effective photographing light beam from an object, a distance between the optical axis and a side defining the opening in a height direction being smaller than a distance between the optical axis and the cut portion of the cut lens.
According to a third aspect of the present invention, there is provided a photographing lens of a camera, comprising:
a cut lens of an oval shape covering a region which allows passage of an effective photographing light beam effective for an imaging screen of a rectangular film; and
a light blocking mask arranged immediately in front of the cut lens and having an opening of an oval shape smaller than the cut lens.
According to a fourth aspect of the present invention, there is provided a photographing lens of a camera, comprising:
a cut lens obtained by cutting a portion of an external form of a circular lens along a chord at a predetermined height from a lens optical axis; and
a light blocking mask arranged immediately in front of the cut lens and having an opening which allows passage of an effective photographing light beam from an object, a distance between the lens optical axis and a side defining the opening in a height direction being smaller than a distance between the lens optical axis and the cut portion.
According to a fifth aspect of the present invention, there is provided a photographing lens of a camera, comprising:
a cut lens, obtained by cutting peripheral portions of a circular lens along two parallel lines at same distance from a center of an optical axis, for transmitting a light beam from an object to at least a rectangular effective recording region of an image recording medium and forming an image of the object on the effective recording region; and
a stray light stopper, arranged in proximity to the cut lens and having an opening reduced from an external form of the cut lens, for preventing harmful reflection light generated in the cut portions of the cut lens from reaching the effective recording region.
According to a sixth aspect of the present invention, there is provided a photographing lens apparatus comprising:
a non-circular lens upper and lower portions of an external circumference of which are cut off parallel with a horizontal line; and
a diaphragm type member upper and lower portions of an external form of which are cut off parallel with a horizontal line, and having an opening which allows passage of photographing-light,
wherein the diaphragm type member blocks off the photographing light above and below the opening.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.